Stream sediment geochemistry and prospecting targets in Harper, Liberia
BAI Yang1,2(), CHEN Kai-Xu3(), CHEN Chong3, LI Fu-Lin3, ZHANG Ji-Chun3, WEI Ling-Xiao2, SI Ke-Fu2, ZHENG Xiong-Wei2, HU Yun-Fei2, WU Ying2, ZHANG Yuan-Pei2
1. Hubei Key Laboratory of Resources and Eeo-Environmental Geology,Wuhan 430056, China 2. Geophysical Exploration Brigade, Hubei Geological Bureau, Wuhan 430056, China 3. Wuhan Center, China Geological Survey (Central South China Innovation Center for Geosciences), Wuhan 430205, China
Birimian rocks, the most significant Au ore-forming rocks in western Africa, are widespread in Harper, southeastern Liberia. As indicated by the geochemical parameters from the 1∶250 000 stream sediment survey of this region, elements Au and Hg exhibit high enrichment and high differentiation while element As manifests enrichment and high differentiation. These findings suggest considerable potential for Au prospecting. Based on the correlation analysis of elements, this study selected factors F1 (for the Au-Hg-Pb-Sn association) and F2 (for the As-Sb-W association) to effectively guide the exploration of gold deposits. Thirteen composite anomalies were delineated by extracting the anomaly information of Au, Hg, As, and Sb from the two principal factors, effectively reflecting the anomaly distributions of different gold deposits or ore occurrences. The geological and mineral surveys in anomaly areas reveal that areas HS1-HS3 and HS12-HS13 with composite anomalies characterized by directional distribution and high intensities show distinct Au mineralization information. Based on this, two major Au prospects, i.e., Seethum New and Behwan, have been identified for further detailed exploration.
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